the proof not only that the prevailing views in regard to the lack of intelligence of such low organisms of the animal kingdom are erroneous, but also that their mental functions may be highly developed without such intricate development of the nervous system as is possessed by the higher organized beings of less psychic capability. I have witnessed how a South-Sea Islander was unable to take off a coat which had been put on him in the regular way. It did not occur to him to stretch one arm backward. The star-fish, however, easily frees itself in the best possible manner from rings, firmly knotted threadings, wrappings, and incumbrances, with which it has not previously come in contact. Such observations must necessarily influence the principles of inquiry. A large brain is required not for one single intellectual act but for a multiplicity. I have found that when many of the tiny ganglionic cells of the Echinodermata remain in organic connection with only one spike, they are capable of doing more work both as to quantity and quality than a smaller number will accomplish under the same conditions. Hence it would appear that also with the higher animals, and with man, the greater intelligence depends on the greater number of ganglionic cells and their combined action rather than on the relatively larger brain. In this way the inquiry into the movements of marine animals directly leads up to the physiology of the brain. Through comparison with that of the animal only is human psychic activity to be understood, for it is the last and highest link of a long chain of evolution whose gradations can only be recognized by the aid of philogeny and physiology—i.e., through the comparison and the history of evolution of functions.
The most attractive problems of the future lie in this direction, and, as soon as the labors in this field have borne more fruit, the different views which now oppose each other will become reconciled. But in other departments of science, too, the perception is dawning that it is of far greater significance to ascertain by comparison the becoming, the growing, the evolution, than to describe the phenomenon by itself just as it happens to present itself to the observer whenever he thinks fit to observe.
In 1861 one of the foremost chemists of the period declared, "The relations of a body to what it has been and to what it may become are the essential part of chemistry" (Kékulé). Instead of "chemistry," we might just as well say "morphology, or history of evolution." The same principle applies to physics, to astronomy, geology, and in a certain sense even to the science of languages. For physics, too, deals with the relations of a conglomeration of forces or of a body to its own past and future. Its ideal is to predict the future of a body, and to estimate its past from its present appearance. Astronomy, in this respect, surpasses all sciences, because its prophecies are being verified with most precision. Geology is essentially the history of the evolution of the globe; comparative philology endeavors, as it were,
